Skin pedicle expansion technique in dorsal nerve fascial Island flap: enhancing viability in repairing digital soft tissue defects.

Purpose: Various flap techniques have been developed for injuries to the middle and distal phalanges, with the dorsal nerve fascial island (DNFI) flap offering distinct advantages. We aimed to elucidate the process of skin pedicle expansion (SPE) during DNFI flap transplantation and its effectiveness in relieving pressure on the fascial pedicle.

Methods: Ninety-two patients with soft tissue defects in the middle and distal phalanges were treated using a DNFI flap from February 2008 to August 2023. Eighty-three patients underwent SPE. The SPE technique involves creating a 3- to 4-mm wide skin strip on the surface of the fascial tissue, which contains a small arterial-venous system along with dorsal nerves, enabling the flap to remain viable. The fascial pedicle reaches the defect area via an incision (the skin channel). The skin pedicle transforms the shape of the channel from triangular to trapezoidal, thereby increasing its capacity. After flap rotation and suturing, the design reduced the pressure of the channel on the fascial pedicle. Theoretically, this should facilitate smoother arterial and venous circulation within the flap, thereby improving survival rates.

Results: All 83 flaps treated using the SPE technique survived. However, one patient experienced flap necrosis, and two patients had partial necrosis in the non-SPE group, with only six patients presenting satisfactory survival outcomes.

Conclusions: SPE may improve the viability of DNFI flaps by alleviating pressure on the fascial pedicle, ensuring adequate blood flow, and enhancing flap viability. SPE has the potential to be a valuable technique in hand-repair surgery.

Level of evidence: Level 4 according to the Oxford Centre for Evidence-Based Medicine (OCEBM).